In many cases, repairable parts that are part of a larger system or machine are not disposed of after they are removed from the system or machine in which they are used. Instead, these “service parts” are, for reasons of cost and time, typically shipped to a repair and refurbishment location and prepared for reuse. The term “repairable part” broadly refers to a part that can be economically restored to a serviceable condition. Typically, a repairable part can be repeatedly rehabilitated to a serviceable condition over a period approximating the life of the system to which it is related. A “service part” is a more generic term which can refer to repairable parts as well as to non-repairable parts (e.g., consumable parts).
The inventory planning for service parts (or, for ease of reference, service parts planning), typically involves, inter alia, balancing the availability of a system against the magnitude of the investment in the service parts for the system. For example, an ample supply of service parts is desirable to maintain continuity in the operations of the system. The capital invested in the service parts, however, is non-revenue generating and perishable if, for example, a service part becomes obsolete.
Service parts planning can be applied to networks having a variety of topologies. These topologies are typically classified based on the number of service parts in the network (e.g., item approach vs. system approach) and the number of hierarchical levels in the network (e.g., single echelon vs. multi-echelon networks). A network having a single type of service part and flat topology is often referred to as a single part single echelon network. A network having a number of different service parts and a two-level hierarchy is called a multipart two-echelon network. A generalized network having an arbitrary number of service parts and an arbitrary number of hierarchical levels is called a multipart multi echelon network.
Conventional service parts planning systems are often directed to single part single echelon networks. These conventional systems, however, do not provide a generalized solution for service parts planning in a multi-echelon network. In addition, these conventional processes do not address certain analytical complexities that arise in multi-echelon networks.